A pioneer of improvisational standup comedy, Jonathan Winters, died Thursday. He was 87.

Winters began his career as a nightclub comic in New York, which earned him guest spots on “The Tonight Show” in the 1960s when Jack Paar hosted it. Later, Winters had a regular role on the final season of Mork & Mindy, playing Mork’s son Mearth. He also appeared in the 90s sitcom Davis Rules, which earned him an Emmy for best-supporting actor.